<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
      <button id="sb">帅哥点击这里</button>

      <script>
          document.getElementById("sb").addEventListener("click",function(){ //在里面的函数就叫回调函数
              alert("傻逼，点什么点！");
          });


        //   let arr=[{name:"唐玮"},{age:20,grade:250}];
        //   let [a,b]=[...arr];
        //   console.log(a);
        //   console.log(b);
        console.log(this==window);//true
      </script>
</body>
</html>